[PATCH 4.14 177/190] kernel/cpu_pm: Fix uninitted local in cpu_pm

Greg Kroah-Hartman
2020-06-19T14:52:36Z

From: Douglas Anderson <dianders@chromium.org>

commit b5945214b76a1f22929481724ffd448000ede914 upstream.

cpu_pm_notify() is basically a wrapper of notifier_call_chain().
notifier_call_chain() doesn't initialize *nr_calls to 0 before it
starts incrementing it--presumably it's up to the callers to do this.

Unfortunately the callers of cpu_pm_notify() don't init *nr_calls.
This potentially means you could get too many or two few calls to
CPU_PM_ENTER_FAILED or CPU_CLUSTER_PM_ENTER_FAILED depending on the
luck of the stack.

Let's fix this.

Fixes: ab10023e0088 ("cpu_pm: Add cpu power management notifiers")
Cc: stable@vger.kernel.org
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200504104917.v6.3.I2d44fc0053d019f239527a4e5829416714b7e299@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/cpu_pm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -89,7 +89,7 @@ EXPORT_SYMBOL_GPL(cpu_pm_unregister_noti
*/
int cpu_pm_enter(void)
{
- int nr_calls;
+ int nr_calls = 0;
int ret = 0;

ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
@@ -140,7 +140,7 @@ EXPORT_SYMBOL_GPL(cpu_pm_exit);
*/
int cpu_cluster_pm_enter(void)
{
- int nr_calls;
+ int nr_calls = 0;
int ret = 0;

ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls);